The Research Of Online Thermal Error Compensation Based On Revolving Body Measuring Machines

Revolving parts are the key parts in the manufacturing sector. They have beenused widely in the fields of industry, aviation, aerospace and defense. With theimprovement of the quality requirements, the urgent needs of the measurement in themanufacturing are high-efficiency and high-precision. So revolving body measuringmachine was appeared. It consists of a rotary table and a number of measuring frames.As the workpiece revolves continuously and the probes move up and down, theworkpiece can be completed all the measurements. This is the effective method foronline measurement. And it became a research hotspot.However, measurement accuracy of the revolving body measuring machine iscritically affected by temperature. It is important to improve the measurementaccuracy. So the temperature error compensation is the key to ensure the accuracy.The traditional method of dealing with the thermal error of the machine tools or thecoordinate measuring machines is to make the online temperature-error mathematicalmodel. And the method has been applied in a number of commercial products. But itis troublesome to set many temperature nodes and present mathematical models. Alsothe compensate results can be affected by external factors easily.In this paper, the method of bidirectional measurement was presented based onthe characteristics of the revolving body measuring machines and revolving parts foronline thermal error compensation. The method is simple and easy to use, andimproves the measurement accuracy significantly. The experiments showed that thiscompensation method allowed the repeatability of the size of the measurement resultsto reduce to about25μm from100μm. And the measurement stability was greatlyimproved.The paper described the structure and characteristics of the revolving bodymeasuring machines firstly. The finite element analysis software ANSYS was used toanalyses the thermal deformation of the machine. From the analysis, the distributionof the temperature, stress and thermal deformation was obtained.Full study on the thermal deformation of the revolving body measuring machinesuggests that the thermal error of the revolving body measuring machine is mainly offset and tilt of the gauging spindle. According to this characteristic, the method ofbidirectional measurement was presented.The paper also discussed the acquisition of compensation dates by measuring thestandard rings and using bidirectional measurement. The compensation dates includedthe distance between the zero Location of probes and the axis of rotation, kissingvalues, the diameters of the fixture, offset and tilt parameters.According to the mathematical model, the software of the real-time temperatureerror compensation system was developed. The system can compensate the resultsautomatically. The experiments showed that this compensation method allowed themeasurement stability improved greatly.Finally, the paper summarized all the work and discussed the prospects of theonline thermal error compensation based on revolving body measuring machines.